Around a year ago my car key fob (the black bit-lock,unlock,alarm) disintergrated due to normal wear & tear & had to be replaced by the dealers at a cost of around THB 700.

Fast foreward to the present; The battery in the key no longer works. Is it possible to have these replaced at say a kiosk in tesco/big C (if so where?) or is it a specialist job that can only be conducted by the dealer?

The battery had been replaced as part of the earlier repair. The original had lasted 7 years.

Depends on the car key / car. Modern cars won't allow it. Average Toyota pickup or sedan, should be ok. But just call the dealer and ask.

The camera shop between all the phone shop, between the food court & Tesco have the batteries. Just take your old one out & show them. Cost me under a hundred Baht for my Toyota replacement.

Cost depends on the type of battery.

Thanks guys, I popped it open to reveal a battery around the size of a 2 bhat coin so i'll have a go at replacing it myself.

If you see a bloke doing this in tescos car park you'll know I locked myself out: